Traditional footwear often have a drawback of reduced ventilation because confining the foot usually does not allow sufficient breathability, which may cause the foot to perspire and may also promote the development of bacteria, fungi and the like as well as any accompanying unpleasant odors and skin problems.
Later developed footwear typically attempted to solve the lack of sufficient breathability by ventilating the shoe. Some constructions have openings in the upper but may also allow debris and water to enter the shoe. U.S. Pat. No. 6,564,475 to Collins, U.S. Pat. No. 5,086,576 to Lamson, U.S. Pat. No. 6,553,690 to Di Girolamo, and U.S. Pat. No. 5,992,052 to Morris appear to relate to footwear with vent holes in the upper, sole, or both. Another disadvantage may be that although the shoe has vent holes in either the upper or sole, breathability may still be inadequate since the shoe lacks a mechanism that draws atmospheric air into the shoe and expels hot air from within the shoe.
Complicated valve arrangements may have been provided by other constructions to open and close an opening to reduce the amount of debris or water entering the shoe. However, these types of footwear may generally be more expensive to purchase. U.S. Pat. No. 6,282,813 to Squadroni and U.S. Pat. No. 5,992,052 to Moretti appear to relate to footwear having valves for venting the shoe.
Other approaches may include a pump encased within the shoe, sometimes in communication with openings in the upper. Generally, the weight of the foot is used to compress the pump and force air out of apertures to ventilate the foot. However, problems may arise if the pump fails to reinflate, which often occurs because the foot is typically placed on top of the pump and prevents full inflation. Moreover, such mechanisms are typically prohibitively expensive to build into footwear and, given that most of these devices are built into the shoe, they are not easily repairable or replaceable. U.S. Pat. No. 4,835,883 to Tetrault and U.S. Pat. No. 4,776,110 to Shiang and U.S. Publication No. 2002/0011009 to Pan appear to relate to footwear having pumps.
What is desired, therefore, is a shoe that has a ventilation system that cools the user's foot and provides sufficient breathability. What is also desired is a shoe with a ventilation system that reduces the amount of debris or water that enters the shoe. A further desire is a shoe that has a ventilation system that is reliable and inexpensive.